1. Field of the Invention
This invention relates to a new system for controlling the operation of a heat exchanger means and to a new control device for such a system as well as to new methods of making the system and the control device.
2. Prior Art Statement
It is known to provide an electrical system for controlling the operation of a heat exchanger means, the system comprising a first electrical transformer having a primary winding and a secondary winding, a relay means for causing the heat exchanger means to be in one condition thereof when the relay means is activated and for causing the heat exchanger means to be in another condition thereof when the relay means is deactivated, electrical circuit means interconnected to the relay means and the secondary winding and having switch means therein for placing the relay means across the secondary winding in a manner to activate the relay means when the switch means is in one condition thereof and to deactivate the relay means when the switch means is in another condition thereof, control means operatively interconnected to the circuit means and being adapted to determine when the relay means should be activated and when the relay means should be deactivated, and a second transformer having a low voltage high current winding disposed in the circuit means in a manner to be in series with the switch means when the switch means is in one condition thereof so as to supply power to the low voltage high current winding and to increase the current flow from the secondary winding of the first transformer through the relay means to activate the relay means. For example, see FIG. 1 of this application wherein the switch means of the prior known system is operated by a relay coil.
However, it is also known to have such a switch means comprise a triac that has its gate operated by a signal directed directly thereto from the control means of the system, such prior known system also having the second transformer provided with only two windings of which only one has its opposed ends interconnected to the control means of the system.